Continuous-current electric motor and generator.



PATENTED SEPT. 4, 1906.

L. TORDA. CONTINUOUS CURRENT ELEOTRIG MOTOR AND GENERATOR.

APPLICATION FILED MAY 6,1905.

WITNESSES mmron Lucia {y 7Zrda Y 62! I nramvzrs.

- brieily, reluctance in the machine.

Lunwie TORDA, 0F BARKING, ENGLAND.

CONTINUOUS-CURRENT ELECTRIC MOTOR AND GENERATOR.

Specification of Letters Patent.

Patented Sept. 4, 1Q06.

Application filed Kay 8, 1905. Serial No. 259,116.

To all whom it may concern:

Be it known that I, LUDWIG TORDA, a subjcct of the Emp *roi' of Austria-I-Iungary, residing at Barking, in the county of Essex, England, have invented certain new and useful Improvements in Continuous-Current Electric Motors and Generators, of which the following is a specification, such as will enable those skilled in the art to which it appertains to make and use the same.

This invention for improvements in continuouscm'rent electric motors and generators has for its principal object to effect a speed variation of the motors or a voltage regulation of the dynamos. For this purpose I apply the rinciple of the variation of the resistance oi the magnetic circuits or,

v Electrical machines in which this general rinci pie is applied are already known; ut in these previous constructions masses of iron have been inserted in the magnetic circuit in. close )roximity to the air-gap, where they have been under the magnetic influence of the armature.

By means'of the construction hereinafter described and claimed I discard the separate appnratusthat i1cld-regulat1ng resist anceand by this means diminishing the cause of troubles and insuring a continuous smooth speed regulation, whereby the number of diiierent speeds obtainable is unlimited, and While these results have already been obtained by previous constructions, involving great constructional di'iiiculties because of the con'iparativcly heavy masses moved or relatively complicated devices applied, I obtain the variation of thc reluctance by forming air ducts or passages inside the stationary field-magnet system running at right angles or approximately at right angles to tho magnet-lines and by udjustably arranging therein pnrannignctic plates adapted when fully inserted to iill or nearly iill the ducts.

The invention is fully disclosed in the following specification, of which the EWCOIDlHb nying drawings form n part, in which the separate parts of my improvement are designated by suitable reference characters in each of the views, and in which Figure 1 is a side elevation, partly in section, oi a dynamic machine with my improvement arrangeil thereon. Fig.- 2 is a similar ince view thercof,.partly in section,

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and showing the air-ducts which I employ; and Figs. 3 to 8, inclusive, are modifications of the air-ducts shown in Fig. 2.

In the drawings forming part of this specification I have shown at g a yoke of a dynamic machine and on one side of which is mounted a casing p, held to the yoke g by means of screw-threaded rods or bolts 0, and the yoke g is provided with a plurality of field-coils m, provided with pole-cores '11, said pole-cores in the form of construction shown in Fig. 2 being provided with a passage or air-duct 0.

Slidably mounted on the rods 0 is an iron therewith the aramagnetic plates (1, thereby increasing or iminishing the air-space in the air-ducts o'correspondingly, and these airdu'cts, similar to the air-ducts between the field and armature, subdivide the field-magnet systcm into several parts, and the variation of the reluctance is obtained by pushing in or pulling out the paramagnetic plates a in the air-ducts 0. r

The advantages of placing these air-ducts and plates inside the field-magnet system, especially in parts of the polecores remote from the armature, are as follows:

First. The prevention of eddy-currents in the adjustable plates and in connection with this constructional and economical advan- Thc. air-gaps oi the improved Inachines may be made smaller, as the setting up of eddy-currents is avoided by the abolitionof massive iron parts in close proximity to the armature-surface, and the smaller the air-gap the thinner and lighter 'ciin the iron plates bemade in order to obtain'a certain 'range of regulation, and at the same time the construction, as will be seen.

- 'the massesof the movable iron plates are rethe eld-c'oils. Magnetically the ring has the advantageous effect of reducing somewhat the reluctance of the yoke; but as a sub: stantial advantage the direct attaching of the plates to an llOIl ring means a considerable simplification and cheapening of the Third. A considerablereduction the weight ofthe movable masses. j I

' Bym arrangement of he air-ducts inside the fiel -magnet systems in positions where" the magnetic induction has the greatest value duced to a minimum. .As the width of the air-ducts and correspondingly the thickness of the plates is small, the masses which are to be moved are comparatively small.

1 I am aware that adjustable blocks of iron, 1

' netic resistance or reluctance of the magnetic pole-pieces of dynamos and motors or between the armature and;the poles of such machines forthe purpose-of controlling the magcurrents; but all such devices require more or i eddy currents, derogatory ciency of the apparatus, whi e my invention the'adjustable thin"paramagless ,heavy masses of iron, which latter are subjected to the influence, of the so-called to the eifiby means of netic plates laced in slots or air-ducts and approximate y rectangular to the direction of the magnetic lines and remote from the airgap between the armature and the magnetpoles are not subjected to such objectionable eddy-currents, and thereby very materially contribute to the eflicienc of the apparatus.

it may be mentioned t at. withregard tocommutation it is immaterial whetherthe increase of the length of the air-path ofthe magnetic circuit is varied inside the fieldmagnet system or directly on the air-gap, as the fact is that the commutation property of a COIltlIlLlOllSrOlllIGIlt machine ispractically not affected by altering the-length of the airgap between the armature and thepole-shoe surface.

Thisinvention permits of the application of a light mechanical devicewhich is most effective, reliable, and simple, and therefore cheap in manufacture. It can be applied to any type of machine, being equally adapted machine.

for small motors and dynamos, as well as for large sizes, as used for rolling-mills, &c. The range of speed regulation can be easily made considerable'as,-for instance, is. often re-.-

quired for printing-machines, &e.this Without affecting the good general working of the The device can be applied at any part of the field-magnet system, as preferred. The air-ducts and plates can be placed, for

iron cores, Figs. 4, 5, 7, may be left at opposite sides of the air-ducts, or the core may be cut' through entirely and distance-pieces r, Fig. 6, inserted to correspond with the depth ofthe air-duct. These distance-pieces, if

formed of iron, become'highlysaturated,but

can be made of non-magnetic materials, if preferred. 3 The plates can also be Wedgeshaped and the air-ducts correspondingly formed, if preferred. This form is shown in Fig. 8,.where 'i is the wedgeshaped plate, k the air-duct formed correspondingly, and 1 1 portions of the field magnet system. v

The principle of reluctance variation on which the application of this more general sha e is based is the. simultaneous alteration of t c section and of the length of the air-path inside of the field magnet system, whereby at thesame time the air reluctance isshunted b an iron reluctance. The principle is applied also in the above-described more special cases, where the air-ducts and the plates are "surrounded by parallel planes.

, The subject of this invention is applicable for. bipolar and multipolar machines, as well as for open or inelosed types, and also for machines with horizontal or vertical shafts.

It will be apparent that variousmean for moving the paramagnetic plates inwardly and outwardly may be employed, and various other modifications of the construction herein shown and described may be .made without departing from the spirit of my invention or sacrificing its advantages, and, with this reservation' What I claim as new, and desire to secure by Letters Patent,.is-

1 In anapparatus for varying the speed of continuous-current motors, a field-magnet system; a. yoke, a plurality. of magnet-cores, and an: iron plate adjustably mounted in an air-duct in the field magnet system between each; magnet-core and the yoke, substantially as shown and described,

.2. In. a,dynamic machine, comprising a yoke, a. plurality of field-magnets arranged therein, a; ring slidably, connected with said yoke and movable toward and from the same, a plurality of; paramagnetic plates secured to said.ring;.ea ch of said 'platesbeing movable transversely of said yoke; between a eorrespending; one of said field magn'ets and said yoke. and means for movingsaidring, sub stantially asshownand described. I

.3. In a dynamic machine comprising a 1 For constructional reasons portions 1" of the .70

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tmnsversoly 0f said yoke between a colre- I my in ention ha spondmg one of sald field-magnets and send 1 presence of the S1111 yokq, and means for moving sand r111 c0m 1 20th day of April, 1

p7 pnsmg a screw-threaded spmdle operating therein, and means for rotating said spindle Nitnessses:

substantially as shown and described. H. D. J

In testimony that I chum the foregoing as F. L. in u 

